Done Need help with sentence below

[stlwright]

二人が重ねてきた日々を人に理解してもらうのは難しいだろうし...
It's probably difficult for two people to get an understanding of each other day after day

重ねてきた-how is this used here?

 

[mikkih]

人に理解してもらうのは難しいだろう:
It's probably difficult for two people to ---> It's probably difficult for others to understand ...

二人が重ねてきた日々:
the (many) days the two spent (together);
the days/time they/the two went through together

 

[Aarowaim]

重ねる is more or less 'gather'. きた is in fact the verb 来た, or 'came'. When you see きた tacked onto the end of another verb, it means 'came to be'. Thus, 重ねてきた means basically the same thing as '...that have been gathered' in this context. Essentially, the sentence is something like, 'It's probably tough for other people to understand the history those two have'.

Also, 二人 is commonly used as a pronoun, for example, 'Hey you two', or 'How have you both been?'. I don't often see 二人 used to count; I usually see 二つ, which literally means 'two (of an object)', for example, the two firefighters, which would probably be 二つの消防士.

 

[mikkih]

* the (many) days the two spent (together);　This is the equivalent of Aarowaim's word choice, "history."

I may prefer more standard translations, but depends on the context, variations could be:

* the days/time they/the two went through together-- if they had hard a life/time together

* the days/time they had for each other - if talking about loving relations for example

Definition of くる　(きた in this sentence):
Definition 9-イ　on the google dictionary link (in Japanese)

二人(が) ... : あの二人；　（あなた達）二人；　（彼ら）二人　are used for 2 individuals. Always use 人 to count people.

二つの消防士 ---> 二人の消防士（が）, 消防士が二人, 消防士の二人（が）

 

[Utsune]

Also, 二人 is commonly used as a pronoun, for example, 'Hey you two', or 'How have you both been?'.

I think you're thinking of 二人とも:

お二人とも元気？
二人ともかわいい！
両親が二人とも
おい貴様ら yo二人とも

Technically it should be "Hey, the two of you" and "How have (the both of) you been?" It's just common 'slang' that we turn them into some sort of pronoun form. Just my two cents.